Method of making heat exchange devices



p 6 1955 c. s. GREER, JR

METHOD OF MAKING HEAT EXCHANGE DEVICES Original Filed Oct. 8, 1951 2 Sheets-Sheet l INVENTOR.

CARL 3 GR EER Jr.

p 6 1955 c. s. GREER, JR

METHOD OF MAKING HEAT EXCHANGE DEVICES Original Filed Oct' 8, 1951 2 Sheets-Sheet 2 IN "EN TOR.

o CARL $.GREER Jr.

United States Patent METHOD OF MAKING HEAT EXCHANGE DEVICES Carl S. Greer, Jr., Albion, Mich., assignor to Tranter Manufacturing, Inc., a corporation of Michigan Original application October 8, 1951, Serial No. 250,273. Divided and this application October 20, 1952, Serial No. 315,723

2 Claims. (Cl. 29157.3)

This invention relates to an improved method of making heat exchange units and is a division of my copending application Serial No. 250,273, filed October 8, 1951, now abandoned.

More particularly, the invention concerns itself with a method of producing a radiator structure especially suitable for installation in a relatively small space such, for example, as the space normally occupied by the base boards of building walls. According to this invention the radiator structure includes a panel or plate which may serve as a base board for a building wall or partition, and which is embossed in an outward direction to form substantially parallel vertically spaced inwardly opening recesses for receiving the adjacent sides of a pair of tubes. The walls of the recesses correspond in cross sectional contour to the contour of the adjacent sides of the tubes and are respectively intimately secured to the tubes to provide a highly eflicient heat conducting joint therebetween. Thus the panel or plate not only serves to conceal the tubes, but in addition, functions as a support or anchor for the tubes. Moreover the above construction renders it possible to employ standard preformed tubes which are produced in large quantities for many uses and hence are relatively inexpensive.

It is still another object of this invention to increase the heat exchange efficiency by providing each tube with an applied fin in the form of a strip reversely bent at longitudinally spaced points to form a series of cormgations. When the strips are applied to the tubes the corrugations cooperate to form a plurality of vertical air passages, and the corrugations of the strips on the respective tubes are offset laterally with respect to one another so that the walls of the corrugations associated with the top tube are respectively positioned in the air streams passing upwardly between the walls of the corrugations associated with the bottom tube.

It is a further object of this invention to form aligned recesses in the edges of the corrugations adjacent the tubes for receiving the inner sides of the tubes. The marginal edges of the recesses are turned laterally outwardly axially of the respective tubes to provide flanges which are shaped to contact the tubes throughout their extent and are secured to the tubes.

The foregoing as well as other objects will be made more apparent as this description proceeds, especially when considered in connection with the accompanying drawings wherein:

Figure 1 is a fragmentary front elevational view of a heat exchange device embodying the features of this invention;

Figure 2 is a fragmentary longitudinal sectional view taken on the line 2-2 of Figure 1;

Figure 3 is a cross sectional view taken on the line 3-3 of Figure 1;

Figure 4 is a fragmentary perspective view of the heat exchange device; and

Figure 5 is an elevational view illustrating the various 2,715,802 Fatented Sept. 6, 1955 steps in the method of producing the fin employed in the heat exchange device.

The heat exchange unit selected herein for the purpose of illustration is in the form of a radiator adapted for installation within a room at the base of one or more of the room walls. Such radiators extend for a substantial distance along one or more walls of the room to be heated, and are formed of a plurality of individual sections removably secured together at adjacent ends to provide a continuous radiator structure. The sections are ordinarily similar in construction, and hence only one section is shown and described herein.

With the above in view, reference is now made more in detail to the drawings, wherein the numeral 10 designates a radiator section comprising an outer panel 11, finned tubes 12 through which a suitable heating medium is circulated, and an air deflector part 13 at the top of the radiator section. The panel ll is preferably in the form of a sheet metal plate having a length which approximates the length of the radiator section and having a width slightly less than the overall width of the radiator section. When installed the panel 11 faces the interior of the room, and serves as a baseboard for the adjacent wall or walls of the room. In any case the panel 11 is embossed in a laterally outward direction at Zones spaced vertically from each other a distance corresponding to the specified spacing between the tubes 12.

The embossments extend lengthwise of the panel 11 and form substantially parallel inwardly opening recesses 14, contoured to respectively receive the front sides of the tubes 12. The top edge portion 15 of the panel 11 slopes inwardly and has a downwardly turned reinforcing flange 16. The bottom edge portion of the panel 11 is also turned laterally inwardly to provide a reinforcing flange 17, and this flange is usually spaced vertically above the room floor by suitable mounting brackets (not shown) to provide an air intake opening beneath the radiator section.

The tubes 12 are formed of metal such for example as steel, and are preferably circular in cross section. These tubes may be of the seamless type, although tubes rolled from sheet metal and having fluid-tight seams may be employed. in practice standard tubes produced in great quantities for the tube consumer trade are used. Thus it is not essential to fabricate special tubes for the radiator sections disclosed herein, and the tubes form fluid passages independently of the panel 11. It has been stated above that the tubes 12 are circular in cross section, and it will be noted from Figure 3 of the drawings that the walls of the recesses 14 are curved on a radius determined so that the inner surfaces of these walls respectively contact throughout their cross sectional area the adjacent side walls of the tubes 12. Also in practice the tubes 12 are respectively hydrogen-brazed to the walls of the recesses 14 in order to assure transfer of heat between the tubes and panel 11 with a minimum loss. Moreover the construction is such that the panel 11 also serves to secure the tubes 12 in proper spaced relationship on the radiator sections. Upon reference to Figure 2 of the drawings, it will be noted that the extremities of the tubes 12 are offset laterally inwardly with respect to the panel 11 in order to provide clearance for coupling the extremities of the tubes 12 to the tubes of adjacent sections.

In order to increase the efliciency of the radiator section, fins 18 are respectively secured to the tubes 12 at the inner sides of the latter. 12 comprise a substantially continuous length of sheet metal which extends lengthwise of the adjacent tube, and is alternately bent in opposite directions to provide a plurality of corrugations 19. The opposite side walls 20 of the corrugations extend in substantially parallel planes The fins 18 on each tube perpendicular to the adjacent tube 12, and the opposite edges of the walls 29 are integrally connected by end walls 21, which extend generally perpendicular to the side walls 20.

The edge portions of the corrugations adjacent the re spective tubes 12 are cut away intermediate opposite ends of the corrugations to provide aligned substantially semicircular recesses 22. The recesses 22 have a radius determined to receive the inner side of the adjacent tube 12, and the marginal portions of the recesses are bent laterally outwardly to provide flanges 23-. The flanges 23 are secured throughout their circumferential extent to the wall of the adjacent tube 12, and in the present instance are preferably hydrogen-brazed to the adjacent tube 12 in order to assure the transfer of heat with a minimum loss. It is to be understood that the end Walls 21 of the corrugations at the recessed edges of the latter are free from connection with the flanges 23 and terminate at opposite sides of the adjacent tube.

in assembly the fins 18 provide vertical air passages at the inner sides of the tubes 12, and the fins on the respective tubes are preferably staggered with respect to one another, so that the walls of the fins on the top tube are actually located in the air streams flowing upwardly between the fins 18 on the bottom tube. The air passes into the radiator section beneath the bottom edge of the panel 11 and is discharged back into the room over the top edge of the panel 111. In this connection it will be noted that the section 13 is secured to the fins 18 on the top tube 12 and has a deflector plate 25 which cooperates with the top edge of the panel 11 to form an air passage 26.

Referring now to the method of making the fins 18 and with special reference to Figure 5 of the drawings, it will be noted that the reference numeral 27 designates a flat strip of sheet metal having a length predetermined to form the fins 18. The strip 27 is subjected to a number of forming operations, which may be economically performed by advancing the strip through a progressive die, not shown herein. The first step in the operation is to form a semicircular recess 29 and associated notches 30 in the front end of the strip as the latter enters the die. The recess 29 has its center on a line L extending lengthwise of the strip midway between opposite longitudinal edges of the strip, and the notches 30 extend laterally outwardly from the front of the recess 29 to provide extensions of the latter.

The strip 27 is then advanced in the die and the marginal edges of the recess 29 are turned laterally to form the flange 23. The flange 23 has a width less than the depth of the notches 39, so that the front ends of the strip may be subsequently bent along the broken lines 31, without interference from the flanges 23, to provide the flanges 32, shown best in Figure 2 of the drawings.

At the same time the recess 29 is flanged, an opening 33 may be formed through the strip 27. The opening 33 comprises substantially semicircular recesses 34 and 35 having their respective centers located on the line L and being separated by notches 36. The strip 27 is then again advanced to a station in the die where the marginal edges of the recesses 34 and 35 are turned laterally outwardly to provide the flanges 23. As stated above the flanges 23 are of less width than the depth of the notches 36 to avoid interference with the flanges when the strip is later bent to form the corrugations. At the same time the recesses 34 and 35 are flanged, another opening 33 is formed in the strip 27, and the above operations are repeated until the required number of flanged openings 33 are formed in the strip. At the rear end of the strip 27 a flanged recess 38 similar to the recess 29 is formed.

Upon completion of the above operations, the strip is bent laterally in one direction along the broken lines 39 and then in the opposite direction along the broken lines 40 to form the corrugations or tins. It will be noted that the broken lines 39 respectively coincide with the opposite side walls of the notches 36 so that bending of the strip about the lines 39 is accomplished without interference from the flanges 23. It will also be noted that the metal between the broken lines 39 and 40 form the walls 21 of the corrugations. The strip 27 is further bent along the broken lines 31 at the extremities thereof to form the flanges 32, and these broken lines also respectively coincide with the notches associated with the recesses 29 and 38 to avoid interference with the flanges 23 during the bending operation.

What I claim as my invention is:

l. The method of forming a heat exchange unit having a tube and having fins applied to said tube, which comprises forming an elongated flat strip with longitudinally spaced aligned openings elongated in the direction of length of the strip and spaced inwardly from opposite side edges of said strip, notching the strip at opposite sides of the openings and midway between the ends of said openings to provide the openings with aligned extensions, bending the portions of the strip defining the marginal edges of each opening at opposite sides of the extensions laterally outwardly to provide flanges extending at right angles to the strip and having a width less than the depth of the extensions, folding the strip in a laterally inward direction along longitudinally spaced lines located between adjacent openings, folding the strip in a laterally outward direction along longitudinally spaced lines which respectively coincide with opposite side edges of the extensions and which extend in parallel relation to the lines along which said strip is bent in a laterally inward direction to form longitudinally spaced corrugations with aligned open recesses in opposite side walls of each corrugation and to position the flanges in alignment to provide extended bearing surfaces bordering the recesses, ositioning a length of tubing in the recesses and securing the length of tubing in seating engagement with the bearing surfaces formed by said flanges.

2. The method of forming a heat exchange unit having tube and having fins applied to the tube, which comprises forming openings through an elongated flat strip between opposite longitudinal edges of the strip and at aligned zones spaced from each other lengthwise of the strip, notching the strip at opposite sides of the openings and midway between the ends of said openings to provide the openings with aligned extensions, bending the portions of the strip defining the marginal edges of each opening at opposite sides of the extensions laterally outwardly to provide flanges extending transversely of the strip and having a width less than the depth of the extensions, folding the strip in a laterally inward direction along laterally spaced lines located between adjacent openings, folding the strip in a laterally outward direction along longitudinally spaced lines which respectively coincide with opposite side edges of the extensions and which extend in parallel relation to the lines along which said strip is bent in a laterally inward direction to form longitudinally spaced corrugations with aligned open recesses in opposite side walls of each corrugation and to position the flanges in alignment to provide extended bearing surfaces bordering the recesses, positioning a length of tubing in the receses and securing the length of tubing in seating engagement with the bearing surfaces formed by said flanges.

References Cited in the file of this patent UNTTED STATES PATENTS 394,711 Worcester .luly 28, 1908 1,776,080 Murray Sept. 16, 1930 1,797,030 Steenstrup Mar. 17, 1931 2,427,336 Askin Sept. 16, 1947 2,462,511 Kramer Feb. 22, 19-49 2,571,505 Waldron Oct. 16, 1951 2,672,32 Weiss Mar. 16, 1954 

